Motion picture projecting machine and the like



Dec. 1, 1931. A. s. HO WELL 1,834,707

MOTION PICTURE PROJECTING MACHINE AND THE LIKE Filed Jan. 4, 1929 Y 2 Sheets-Sheet 1 y" MevM, W3

Dec. 1, 1931. A. s. HOWELL 1,834,707

' MOTION PICTURE BRQJECTING MACHINE AND THE LIKE Filed Jan. 4, 1929 2 Sheets-Sheet 2 Patented Dec. 1, 1931 UNITED STATES PATENT OFFICE ALBERT S. HOWELL, OF CHICAGO,-ILLINOI S, ASSIGNOR TO THE BELL & HOWELL COMPANY, OF CHICAGO, ILLINO IS, A CORPORATION or ILLINOIS MOTION PICTURE PROJECTING MACHINE AND THE LIKE Application file d January 4, 1929. Serial No. 330,200.

My invention relates particularly to motion picture projecting machines although not limited to this use alone. p

One of the objects of my invention resides in the provision of a simple and effective intermittent feed mechanism which is particularly adapted to and which preferably does increase the rest periods as compared with the feeding periods thereof, and which is adapted for a certain well known type of motion picture projecting machine without necessitating radical changes of the machine.

Another object of my invention resides in the provision in a motion picture projecting machine of a simple and effective intermittent feed and light shutter mechanism which is adapted for the purposes of the projection of adequate light having the appearance of being continuously projected, and which isadapted for the aforementioned well known type'of motion picture projecting machine.

With these objects in view my invention consists in certain features of novelty in the construction, combinationand arrangement ofparts by which the said objects and certain other objects, hereinafter appearing, are effected, all as fully described with reference V to the accompanying drawings and more particularly pointed out in the appended claim.

In the said drawings Figure 1 is a side elevation of a motion picture projecting machine embodying my in vention Figure 2 is an interior view on the line 22 of Figure 1; I

Figure 3 is a section on the line 3-3 of Figure 2;-

Figure 4 is a partial section on the line 4-4 of Figure 2; and 4 Figure 5 is apartial perspective view of the intermittent feed shuttle of the mechanism, hereinafter described.

Like characters of reference indicate like parts in the several views.

Referring to the drawings, 1" designates generally thebody of the machine which is inclusive of a transverse support member 2. See Figures 1 and 2.

'Secured on and disposed at, one side'of the.

support 2 in a transverse plane corresponding screws .6 the block therewith is a vertically extending apertured intermittent film feed guide 3 which may be of any suitable design, but which is preferably of the type described and claimed in my co-pending application for U. S. Letters Patent, Serial No. 326,015, filed December 14, 1928, for improvement in perforated strip feed mechanism, in which application certain other mechanism shown 011 the drawings herein is also described and claimed.

Mounted for vertical adjustment in a vertical groove 4: in the rear face of the support 2 adjacent the side thereof opposite that on which the guide is disposed is a pivot mounting block 5 which is secured in adjusted position in the groove 4; by means of headed passing through vertical slots 7 in and screw-threaded into, the'support 2. See Figures 2 and 3.

A lever like feed shuttle 8 is pivoted at one of its ends on the block 5, bymeans of a pivot mounting 9 disposed on'a rearwardly and forwardly extending axis, for movement in a transverse plane corresponding with the plane of the guide. The other end of the shuttle 8 is provided with a film per foration engaging ratchet tooth 11, see particularly Figure 5, which is tensioned into the plane of a film 12 in the guide for engagement in perforations 13 of the film to feed the film with downward movement of the shuttle and to slide over the'film with lipward movement of the shuttle, a marginal opening 14 being provided in the rear face guide member of the guide forthe tooth 11. A torsion spring 15 surrounds the pivot mounting 9 and has one end thereof secured with the block 5, as designated at 16, and has the other end thereof engaged with the shuttle 8, as designated at 17 for operating the shuttle upwardly or through its return or non feeding stroke. I g A revoluble shaft 18 is disposed on a rearwardly and forwardly extending axis and is journaled in and extends through a bore through the support 2 and is disposed intermediate the guide 3 and the pivot mounting 9. See Figures 2 and 3. I I Secured on the shaft 18 immediately to the rear of the support 2v is a radial cam 19 which is engaged by a cam roller structure 21 on the shuttle 8 intermediately of the ends thereof, the spring 15 yieldably urging the shuttle upwardly and maintaining the cam roller structure engaged with the cam whereby rotation of the cam effects oscillation of the shuttle through its feed or downward stroke and its return or upward stroke.

The cam 19 is provided with a feed portion 22 which is abnormally small in angular extent, which, as shown, is approximately 30, and on either side of the feed portion are dwell portions 23 which are separated opposite the feed portion by a return portion 24 of abnormally great angular extent. Thus the angular extent of the feed portion 22 has a relation with the angular extent of the remainder of the cam by which the angular ex tent of the remainder of the cam is abnormally greater than the feed portion in the-order of an abnormally high multiple thereof.

The return portion 24 is of an angular extent greater than the angular extent of the feed portion 23 in the order of an abnormally high multiple of the angular extent of the feed portion, and, as shown, is greater than one half of the angular extent of the cam, thus providing a slow return movement of the shuttle with obvious advantage.

The extent of the portions 22, 23 and 24 of the cam 19 is indicated by the radial dot and dash lines in Figure 2.

By reason of the fact that the angular extent of the feed portion 22 is abnormally small, the rest periods of the film 12 in the guide are abnormally great, thus permitting long projection periods and a correspondingly great aggregate projected light.

A light shutter 25 is secured on the shaft 18 immediately to the rear of the cam 19 and the shuttle 8 for the purpose of covering the light aperture 26 of the guide 3 during intermittent movement of the film in the guide, and, in order that the intermittent light impulses may be of such frequency as to be im perceptible as such, the shutter is constructed as follows. See Figure 2.

The shutter is provided with a plurality, three as shown, of equally spaced shutter blades 27 for covering the aperture 26 of the guide and each blade has an angular extent corresponding with the angular extent of the feed portion 22 of the cam 19, so that each of the blades cover the aperture 26 for a period approximating the period of movement of the film in the guide, one of the blades serving to cover the aperture while the movement of the film takes place while the others effect interruption of the projected light for equal periods and at equally spaced intervals of relatively high frequency which tends to render the light impulses imperceptible as such.

By reason of the abnormally short angular extent of the feed portion 22 of the cam, predominating light impulses are ellected, it be ing observed that the angular extent of the light openings between the blades 27 are considerably greater than the angular extent of the blades.

Referring to Figure 1, the machine is driven from an electric motor, not shown, enclosed within a portion 28 of the body disposed rearwardly of the support 2 and shutter 25, and for the purpose of driving the mechanism from this motor a gear 29 is secured on the rear face of the shutter and is thus fixed with the shaft 18, as shown in Figures 2 and 3.

Referring again to Figure 1, the film 12 is fed to and from the ends of the guide 3 by constant film feed means disposed forwardly of the guide 3 and support 2 and which is inclusive of constant film feed sprockets 31, and these are driven, in a manner unnecessary to be described, in timed relation with the intermittent feed mechanism heretofore described, from the shaft 18 projecting forwardly from the support 2.

WVhile I have described and shown the preferred embodiment of my invention I do not wish to be limited to the precise details of construction as changes may readily be made without departing from the spirit of my invention, but having thus described my invention, I claim as new and desire to secure by Letters Patent the following:

In a motion picture projecting machine the combination with an apertured film guide, of a lever like feed shuttle pivoted at one end for movement in a plane corresponding with that of said guide and provided at its other end with a film perforation engaging tooth device, a revoluble cam disposed on an axis extending in correspondence with the axis of said shuttle and disposed intermediate the axis of the shuttle and said guide and opcrative upon said shuttle intermediate its ends for effecting feeding and return strokes of the shuttle, the angular extent of the feed portion of the cam being approximately 30, and a revolving light shutter fixed with said cam and provided with three equally spaced shutter blades for covering the aperture of said guide, each blade having an angular extent corresponding the angnlar extent of the feed portion of said cam.

In witness whereof I hereunto aflix my signature this 20th day of December, 1928.

ALBERT S. HOWELL, 

